In the field of semiconductor material processing, for example, semiconductor material processing apparatuses including vacuum processing chambers are used performing various processes, such as etching and deposition of various materials on substrates, and resist stripping. As semiconductor technology evolves, decreasing transistor sizes call for an ever higher degree of accuracy, repeatability and cleanliness in wafer processes and process equipment. Various types of equipment exist for semiconductor processing, including applications that involve the use of plasmas, such as plasma etch, reactive ion etching, plasma-enhanced chemical vapor deposition (PECVD) and resist strip. The types of equipment required for these processes include components which are disposed within the plasma chamber, and must function in that environment. The environment inside the plasma chamber may include exposure to the plasma, exposure to etchant gasses, and thermal cycling. Materials used for such components must be adapted to withstand the environmental conditions in the chamber, and do so for the processing of many wafers which may include multiple process steps per wafer. To be cost effective, such components must often withstand hundreds or thousands of wafer cycles while retaining their functionality and cleanliness. There is generally extremely low tolerance for components which produce particles, even when those particles are few and no larger than a few tens of nanometers. It is also necessary for components selected for use inside plasma processing chambers to meet these requirements in the most cost-effective manner.
To this end, brittle components which form, for example, a showerhead electrode, are subjected to a mechanical machining operation, such as drilling in order to form process gas delivery holes therethrough. However, the drilling of holes in the brittle component may result in small, nearly invisible microcracks in the surface of the brittle components. These microcracks or subsurface damage can lead to particle contamination due to fracturing of the brittle material.